An example of a wide moat company is Berkshire Hathaway Inc. According to the shareholder letter of 2013, the compounded annual gain in the period from 1965 until 2013 of Berkshire Hathaway was 19.7% while for the S&P500 it was 9.8%. Berkshire Hathaway CEO and chairman Warren Buffett is widely considered the most successful investor of the 20st century.

On the chart below we can see WMW (red line) underperforming VTI (blue line) during a specific period of more than 3 years and 3 months (excluding dividends)

On the chart below we can see WMW (red line) underperforming RSP (blue line) during a specific period of more than 6 years and 3 months (excluding dividends)

In their newsletter of March 2015, Van Eck informed the readers that they plan to launch another ETF named Market Vectors Morningstar International Moat ETF (NYSEArca:MOTI) which would
seek to track the Morningstar Global ex-US Moat Focus Index. A preliminary N-1A SEC form dated 26th of February 2015 was found at
http://www.sec.gov/Archives/edgar/data/1137360/000093041315000875/c80423_485apos.htm, where the index was described as follows:
"The Global ex-US Moat Focus Index is a rules-based, equal-weighted index intended to offer exposure to companies that the Index Provider determines have sustainable
competitive advantages based on a proprietary methodology that considers quantitative and qualitative factors ("wide and narrow moat companies").
Wide and narrow moat companies are selected from the universe of companies represented in the Morningstar Global Markets ex-US Index (Parent Index),
a broad market index representing 97% of developed ex-US and emerging markets market capitalization.
The Global ex-US Moat Focus Index targets a select group of wide and narrow moat companies: those that according to Morningstar's equity research team are the most
attractively priced as of the quarterly rebalance.
A momentum signal is used to exclude 20% of the wide and narrow moat stocks in the Parent Index with the worst 12-month momentum based on a 12-month price change of
each stock. Out of the companies in the Parent Index that the Index Provider determines are wide or narrow moat companies and display 12-month momentum in the top 80%,
the Index Provider selects the top 50 companies to be included in the Global ex-US Moat Focus Index as determined by the ratio of the Index Provider's estimate of
fair value of the issuer's common stock to the price. The maximum weight of an individual country or sector in the Global ex-US Moat Focus Index is capped at three
times its corresponding weight in the Parent Index at the time of reconstitution, or 25%, whichever is higher.
A buffer rule is applied to current Global ex-US Moat Focus Index constituents. Those that are ranked in the top 125% of the number of stocks in the Global ex-US Moat
Focus Index, as measured by price/fair value will remain in the Index at the time of reconstitution and those that fall outside of the top 125% are excluded from the
Global ex-US Moat Focus Index." [...] "A Moat Committee of the Index
Provider's equity research team makes the final determination of whether a company is a wide or narrow moat company.
Only those companies with one or more of the identifiable competitive advantages, as determined by the Index Provider's equity research team and agreed to by the Moat
Committee, are wide or narrow moat companies. The quantitative factors used to identify competitive advantages include historical and projected returns on invested
capital relative to cost of capital. The qualitative factors used to identify competitive advantages include customer switching cost (i.e., the costs of customers
switching to competitors), cost advantages, intangible assets (e.g., intellectual property and brands), network effects (i.e., whether products or services become more
valuable as the number of customers grows) and efficient scale (i.e., whether the company effectively serves a limited market that potential rivals have little
incentive to enter into). Wide moat companies are those that the Index Provider believes will maintain its competitive advantage(s) for at least 20 years. Narrow moat
companies are those that the Index Provider believes will maintain its competitive advantage(s) for at least 10 years. The Index Provider's equity research team uses
standardized, proprietary valuation models to assign fair values to potential Global ex-US Moat Focus Index constituents' common stock. For a majority of companies,
the Index Provider estimates the issuer's future free cash flows and then calculates an enterprise value using weighted average costs of capital as the discount rate.
The Index Provider then assigns each issuer's common stock a fair value by adjusting the enterprise value to account for net debt and other adjustments. For a minority
of companies, an alternative free cash flow valuation model may be used, such as the Index Provider values companies in the banking industry with estimates of future
free cash flows to equity holders and uses the cost of equity as the discount rate. As of December 31, 2014, the Global ex-US Moat Focus Index included 50 securities
of companies with a market capitalization range of approximately $1.7 billion to $110.1 billion and a weighted average market capitalization of $27.0 billion."